1. Field of the Invention
The present invention relates generally to a metal shelving system and it relates more particularly to a shelving system which can be easily assembled and disassembled and wherein the shelves are readily adjustable to various heights.
2. Description of the Prior Art
Adjustable shelving employing shelves constructed of sheet metal is well known and extensively used in a variety of environments and shelf loading conditions. Shelving of this general type often falls into a category referred to as knock-down shelving because it is capable of being assembled and disassembled time and again. Conventional knock-down shelving employs vertical corner posts designed to have shelves mounted thereon at spaced vertical increments. A cooperating corner structure facilitates the mounting of the shelf to the corner post. While many corner mounting structures of known shelving units have provided adequate strength and rigidity for supporting shelf loads, often these known units are difficult or time consuming to assemble.
In one fairly common type of corner structure used by many conventional shelving units, each shelf is provided with corner structures comprising a closed collar structure defining a vertical opening for accommodating a corner post. With such an arrangement, all four corner posts must be slidably inserted through the collars associated with the corners of each shelf or in the alternative, the individual shelves must be positioned with the collars aligned with the posts so that the shelf can be slid downwardly along the posts into position. Once the collars and posts have been properly interfitted, separate wedge members of fasteners are used to fixedly secure the shelf to the post at the desired height. This type of structural arrangement, however, can be complex and can involve small parts which are easily misplaced. Further, this type of shelving unit does not permit the addition or removal of an intermediate shelf without first requiring disassembly of other shelves disposed either above or below the intermediate shelf. This greatly restricts usage of the shelving because changes in shelf configuration require complex disassembly and reassembly procedures. Examples of such a shelving unit are disclosed in U.S. Pat. No. 3,523,508 and U.S. Pat. No. 3,604,369 issued to Maslow.
Another conventional configuration for known shelving units employs a corner structure which requires the use of threaded fasteners or the like for securing the individual shelves to the corner posts. In units of this type, often times the shelf itself directly connects to the corner posts by threaded fasteners or, in the alternative, a special corner member such as a collar is fitted onto the corner post and then this corner member in turn is secured to the shelf by threaded fasteners. Assembling shelving units of this type can be manually difficult due to the requirement of properly positioning and holding all of the various pieces while at the same time attempting to position and secure the threaded fasteners. Such units often require two persons to accomplish the assembly operation.
Another problem associated with many known shelving units is the complexity with which the supporting corner structure is made. Many of the known corner structures either employ a substantial number of pieces and/or pieces of relatively complex configuration which are expensive to fabricate. Such complex corner arrangements not only undesirably increase the cost of the shelving unit but also can result in complex and difficult assembly techniques. Examples of known shelving units of this general type are disclosed in U.S. Pat. No. 4,582,001 issued to Leikarts and U.S. Pat. No. 4,615,278 issued to Cabrelli.
Accordingly, it is desirable to provide a knock-down shelving unit having an improved corner structure for rigidly securing shelves thereto.
It is further desirable to provide an improved shelving unit which is capable of inexpensive fabrication but yet is reliable under heavy shelf loads.
Still further, it is desirable to provide a shelving unit which can be readily assembled and disassembled without the need for mechanical fasteners or tools and which can be assembled and disassembled by a single person.
Still further, it is desirable to provide a shelving unit in which shelves may be easily reconfigured without the need to disassemble and reassemble any other parts of the unit.
Still further, it is desirable to provide a shelving unit which minimizes the shelf .space dedicated to providing for the shelf support structure thereby maximizing available shelf space.